1. Field
The present invention relates to a light emitting device and a method for manufacturing the same.
2. Related Art
Among flat panel display devices, light emitting device has an advantage in that it has high response speed and low power consumption. The light emitting device can also be manufactured thin in size and light in weight because of not requiring backlight unit.
In particularly, organic light emitting device has an organic light emitting layer between an anode and a cathode. Holes from the anode and electrons from the cathode are combined within the organic light emitting layer to create hole-electron pairs, i.e., excitons. The organic light emitting device emits lights by energy generated while the excitons return to ground state.
FIG. 1A is a plan view of a prior art light emitting device, and FIG. 1B is a cross sectional view taken along line A-A′ of FIG. 1A.
Referring to FIGS. 1A and 1B, the conventional light emitting device 100 comprises a substrate 110, and anodes 120 and wires 125 formed on the substrate 110, each wire 125 comprising a contact part 126 at an end of the wire 125. Wires 125 may comprise a conductive layer 125A and a metal layer 125B disposed on the conductive layer 125A. An insulating layer 130 is formed on the substrate 110 comprising the anodes 120 and wires 125 having contact parts 126. The insulating layer 130 comprises openings 135, each of which exposes a portion of each anode 120, and contact holes 136, each of which exposes a portion of each contact part 126.
Emission layers 150 are disposed within the openings 135 of the insulating layer 130, and barrier ribs 140 are formed on the insulating layer 130 in the shape of reverse taper. Cathodes 160 are disposed on the substrate 110 comprising the barrier ribs 140. The cathodes 160 are patterned by the barrier ribs 140 and connected electrically to the contact parts 126 exposed by the contact holes 136 and the emission layers 150 formed within the openings 135.
As can be seen from a contacting region indicated by alphabet ‘E’ of FIG. 1B, the contact hole 136 is formed to expose a portion of an upper surface of the contact part 126. Therefore, the contacting area of the contact part 126 and cathode 160 becomes narrow.
As a consequence, a peeling phenomenon of the insulating layer 130 can occur at the regions contact part 126 other than the regions exposed by the contact holes 136. And interfacial resistance between the contact part 126 and cathode 160 can be increased because the contacting area between the contact part 126 and cathode 160 are very narrow.